Existing versions of the vortex shedding flowmeter measure fluid velocity only, wherein the fluid velocity is determined from the vortex shedding frequency. A new version of the vortex shedding flowmeter about to be introduced into the flowmeter market measures fluid velocity as well as mass flow rate of the fluid, wherein the mass flow rate is obtained as the ratio of the dynamic pressure determined from the amplitude of the fluid dynamic force associated with the vortex shedding to the fluid velocity determined from the vortex shedding frequency. The Piezo electric transducer commonly employed in the construction of vortex shedding flowmeter's experiences drift in performance due to aging, temperature, depolarization, etc., which drift introduces an error of significant magnitude in measuring the amplitude of the fluctuating fluid dynamic force generated by the vortex shedding, from which the mass flow rate of the fluid is determined. In order to eliminate the error in the measurement of mass flow rate, the drift in the performance of the Piezo electric transducer employed in the vortex shedding flowmeter measuring volume and mass flow rates must be detected and compensated.